+SG_BEGIN_DECL()
+
+int gtnets_initialize(int wsize);
+int gtnets_add_link(int id, double bandwidth, double latency);
+int gtnets_add_route(int src, int dst, int *links, int nlink);
+int gtnets_add_router(int id);
+int gtnets_add_onehop_route(int src, int dst, int link);
+int gtnets_create_flow(int src, int dst, long datasize, void *metadata);
+double gtnets_get_time_to_next_flow_completion();
+double gtnets_run_until_next_flow_completion(void ***metadata,
+ int *number_of_flows);
+double gtnets_get_flow_rx(void *metadata);
+
+void gtnets_print_topology(void);